Dishwasher door counterbalance arrangement

ABSTRACT

Tension springs for counterbalancing a swing-down dishwasher door are nested in outwardly-open, channel-shape support legs for the dishwasher tub, and pivotal connector means which slide along the legs connect the upper ends of the springs to the ends of the lever arms of the dishwasher door bracket so that the springs will be elongated only along their axes and the connectors will pivot to accommodate the varying perpendicular distances between each spring axis and points on the path of movement of the end portion of the lever arm when the door is moved between its opposite positions.

United States Patent Hancock [151 3,704,550 1 Dec. 5, 1972 [S4]DISHWASHER DOOR COUNTERBALANCE ARRANGEMENT [72] Inventor: Charlie L.Hancock, Grove City,

Ohio

[73] Assignee: Westinghouse Electric Corporation,

Pittsburgh, Pa.

[22] Filed: May 11, 1971 211 Appl. No.: 142,307

[52] US. Cl ..49/386, 126/191 [51] Int. Cl. ..E05f l/10 [58] Field ofSearch ..l26/191, 194; 49/386 [56] References Cited UNITED STATESPATENTS 2,837,080 6/1958 Reeves ..l26/191 3,040,731 6/1962 Mudd..l26/191 Primary Examiner-Kenneth Downey Attorney-F. H. Henson and E.C. Arenz [5 7] ABSTRACT Tension springs for counterbalancing aswing-down dishwasher door are nested in outwardly-open, channel-shapesupport legs for the dishwasher tub, and pivotal connector means whichslide along the legs connect the upper ends of the springs to the endsof the lever arms of the dishwasher door bracket so that the springswill be elongated only along their axes and the connectors will pivot toaccommodate the varying perpendicular distances between each spring axisand points on the path of movement of the end portion of the lever armwhen the door is moved between its opposite positions.

10 Claims, 4 Drawing Figures PATENTED DEC 5 I97? 3. 704 550 BACKGROUNDTHE INVENTION Field of the Invention This invention pertains to the artof counterbalancing appliance doors of the swing-down type.

So far as I know, most front opening dishwashers having swing-down typedoors hinged along their lower edges have had their springs attached insuch manner that as the door is moved between opposite positions,

the axis of the spring is at least angularly displaced, and

sometimes is shifted in translating fashion. One example of such anarrangement is US. Pat. No. 3,453,779. While one commercially produceddishwasher does have a spring arrangement in which the lower end of thespring is fastened to the lower portion of a support leg and occupies agenerally vertical disposition, in that arrangement, the upper end ofthe spring follows the arc of movement of the lever arm end so that theaxis of the spring is angularly displaced as the door is moved betweenits opposite positions.

My improved arrangement is intended to provide an arrangement in whichthe spring is confined to movement along its axis so thatthe spaceoccupied by the counterbalancing arrangement is reduced from otherarrangements known to me, and in which an adequately balanced conditionexists throughout the range of movement of the door.

SUMMARY OF THE INVENTION In accordance with my invention, the lever armswhich are attached to each side of the door are dimensioned and locatedso that their end portions move through an arc sufficiently close to theaxis of a channel-shaped support leg that the tension spring may benested in the channel, and a pivotal connecting means, which also partlynests in the channel, connects the upper end of the spring to the endportion of the lever arm and pivots to accommodate the changing distancebetween the axis of the spring and points on the are through which theend portion of the lever arm moves. Thus, the spring is confined in itsmovement to stretching and relaxing along its initial vertical axis sothat encroachment upon other useful space about the dishwasher tub iseliminated.

The pivotal connecting means takes the form of a block which slidesalong the channel-shaped leg. All the coils of the tension spring arespaced from the leg structure to avoid contact therewith and resultantnoise, and with the friction between the slidable block and the legstructure providing a braking effect throughout portions of the movementof the block.

DRAWING DESCRIPTION FIG. 1 is an exploded, isometric view of afragmentary portion of the dishwasher tub and door inner panel, and thecounterbalancing arrangement before assembly;

FIG. 2 is a side view of the pivotal connecting block for connecting thedoor lever arm to the upper end of the tension spring;

FIG. 3 is a sectional view corresponding to one taken along the lineIll-III of FIG. 2; and

FIG. 4 is a fragmentary side view of the counterbalancing arrangement inassembled form with the arrangement as shown in full lines correspondingto the door being closed, and in broken lines with the door being in itsnormally open horizontal position.

DESCRIPTION OF THE PREFERRED EMBODIMENT In FIG. 1, only the right-handportion of the dishwasher tub 10, door inner panel 12 and counterbalancearrangement are illustrated since the leftahand portions of these partsare, for purposes of the invention, mirror images of that shown inFIG. 1. The tub 10 is supported on each side by two support legs 14 and16, both of which are channel-shaped in horizontal cross section, withthe open parts of the channels facing outwardly. On each side of thetub, at the lower front comers, a hinge support bracket 18 is welded tothe tub. Each bracket includes upper and lower forwardly-projectingtongues 20 and 22, respectively, the upper tongue 20 including ahook-shaped end which provides a seat 24 which, .when the inner doorpanel 12 is assembled to the tub, receives a hinge pin 26 carried by thedoor bracket 28.

The door bracket 28 (FIG. 1) includes a base part 30 which is welded tothe lower comer front face of the door panel and a right angle lever armportion 32 which, when the door is assembled to the tub with the hingepin 26 in the seat 24, lies in a plane parallel to the side wall of thetub and spaced slightly outwardly from the support leg 14. Theunattached end portion 34 of the lever arm is formed with anupwardly-open hook which is adapted to pivotally connect with the upperend of the pivotal connector block generally designated 36.

-A tension spring 38 (FIGS. 1 and 4) is provided at each side of thedishwasher and is initially assembled in the arrangement by having itslower end hooked into an upwardly embossed portion 40 of the base of theleg. The embossment has an aperture therein to receive the lower end ofthe spring. The upper end of the spring is attached to the lower part ofthe connector block 36. This holds the door in place.

Referring now to FIGS. 2 and 3, the pivotal connector member 36 ismolded from a material having frictional characteristic such as nylonand basically includes a slide portion 42 adapted to be received in thechannel of the support leg 14, and a connector portion 44 which servesto provide the connection between the lever arm 28 and the tensionspring 38. The slide portion 42 is generally cylindrical throughout mostof its extent with a diameter that adapts it for a free fit within thechannel. The connector portion comprises a pair of spaced apart walls 46and 48 joined at the top by an intermediate circular pin 50 which seatsin the hook end (FIG. 1) of the lever arm, a lower circular pin 52centered with respect to the center of the slide portion 42 and adaptedto have the upper end of the spring 38 hooked thereto, and anintermediate triangular shaped web 54 which serves to strengthen theconnection between the two walls. A metallic insert 56 is positioned ina bore in the upper pin 50 to provide additional strength at thatlocation.

Referring now to FIG. 4, the relationship of the parts in assembled formis there illustrated. The solid line view corresponds to the door beingin a closed, vertical position, while the broken line representation ofthe parts corresponds to the door being in its horizontal, openposition. The open position is limited by the edge 57 of arm 28 engagingtab 59 of bracket 18.

As noted before, the slide portion '42 has a diameter that permits it torotate freely in the channel of the support leg 14. The lever arm 32 isdimensioned and located, relative to the location of the support leg 14,that the are 58 through which the center of the connection at the endportion 34 moves generally follows the orientation 'of the support leg14. Thus, while the are obviously cannot parallel a straight line, thecentered axis of the support leg 14 does trace a chord intersecting theare 58 at, or adjacent, the end points of the arc..

It will also be noted that the end points of the arc, corresponding tothe door being in a horizontal open position, and an opposite verticalclosed position, fall within the span of the web of the leg 14. Thispreferred arrangement limits the degree to which the slider portion 42is pressed against either of the legs forming the channel of the supportleg 14.

As the door is moved from its closed position in which the lever arm 32extends diagonally downwardly asshown in FIG. 4), the pivotal connectormember 36 will pivot within the channel as the axis of the upper pin 50of the connector follows the arc 58. Thus when the door is, say, halfway open, the connector will be pointing diagonally upwardly to theright; and when the door is fully opened, the connector is asillustrated in the broken line position in which it is pointedsubstantially directly upwardly. Throughout this movement, the axis ofthe spring 38 is neither angularly displaced nor translated throughoutthe stretching and relaxing of th spring.

During movement of the connector 36 (FIG. 4) from the solid line to'thebroken line position, as the center line of the connector pin 50 movesto the right of the centered axisof the support leg 14, the sliderportion 42 will tend to bear frictionally against the right side leg ofthe channel to a degree that depends upon the perpendicular distance andthe centered axis of the support leg 14 (which in the arrangement shownis also the spring axis) and any given point on the arc 58. Thisfrictional engagement between the nylon block and the support leg isconsidered desirable in that it yields a feeling of smooth operation tothe person moving the door and effects a degree of braking. It will alsobe appreciated that in the solid line position of the connector, theslider block 42 bears slightly against the lefthand leg of the channelsince the center of the pin 50 is to the left of the-centered axis ofthe support leg.

The spring 38 has a diameter and is located to be spaced from both legsand the web of the channel support leg 14 throughout its movement, eventhough it is nested at least in part in the channel. This prevents anypossibility of rubbing of the spring coils against any part of thesupport leg.

lclaim:

} 1. In a dishwasher including a forwardly-open-face tub and a door forclosing said tub face and hinged adjacent its lower edge, acounterbalancing arrangement for at least one side of said door,comprising:

a lever arm fixed to said door at a side thereof adjacent the lowerportion and having an end portion movable through an arc in accordancewith door movement;

a tension spring for counterbalancing said door at a side of said tub,said spring having a fixed lower end;

means for guiding the upper end of said spring for movement along anaxis substantially coincidence with the axis of said spring; and

pivotal means having a lower end portion connected to said upper end ofsaid spring, and having an upper end portion connected to said lever armend portion so that said pivotal means pivots at both connections toaccommodate the varying perpendicular distance between said axis andpoints along said are. I e

2. In a dishwasher according to claim 1:

said guiding means includes achannel-shaped support leg for said tub,with said channel being outwardly open.

3. In a dishwasher according to claim 2:

said are has end points, corresponding to opposite positions of saiddoor, facing an 'area spanned by the width of the channel of saidsupport leg.

4. In a dishwasher according to claim 2:

said spring is nested in part at least in said channel of said supportleg.

5. In a dishwasher including a forwardly-open face tub and a door forclosing said tub face, said door having a hinge axis adjacent its loweredge, a counterbalance arrangement for at least one side of said door,comprising:

a vertically-disposed leg adjacent the tub front and extending upwardlyalong a side of said tub;

a lever arm fixed to the side of said door, said arm being dimensionedand located that its end portion remote from the door moves through anarc, as said door is moved between its opposite positions, generallyfollowing said leg;

a tension spring having its lower end fixed adjacent the lower portionof said leg;

pivotal connector means having one portion slidable along said leg andhaving the upper end of said spring pivotally connected thereto, andhaving another portion pivotally'connected to said end portion of saidlever arm and pivotal about the connection between said one portion andsaid spring so that said spring is stretched and relaxed along its axiswithout angular displacement therefrom as said end portion of said leverarm is moved throughout its said arc, said pivotal connector pivotingabout both of its said connections to accommodate the varyingperpendicular distance between said axis and points along said arc.

6. In a dishwasher according to claim 5:

said leg is an outwardly-open, channel-shaped member in horizontalcross-section; and

said one portion of said pivotal connector means is received at leastpartly in said channel.

7. In a dishwasher having a forwardly-open face tub and a door having alower edge hinge axis for closing said tub, a counterbalance arrangementcomprising:

a lever arm fixed to each of the opposite sides of said door, each armhaving an end portion remote from said door;

a tension spring at each of the corresponding opposite sides of said tubfor counterbalancing said door;

a vertically-disposed support leg at each side of said tub adjacent thefront thereof;

means fastening the lower end of said spring to the lower portion ofsaid leg;

pivotal connector means for connecting the upper end of said spring tosaid end portion of said lever arm at two pivotal connection locations,said connector means including a slider portion confined by said leg tomovement along an axis coincident with the axis of said spring, saidconnector means including another portion pivotally connected to saidlever arm end portion to provide one of said pivotal connectionlocations, and pivotal about the axis of connection of the upper end ofsaid spring to said connector means to provide the other of said pivotalconnection locations, both said pivotal connections pivoting during doormovement to acanzn commodate the perpendicular distance between the axisof said spring and various points along the arc of movement of said endportion as said door is moved.

8. In a dishwasher according to claim 7:

said support leg comprises an outwardly-open channel, said sliderportion being received in said channel.

9. In a dishwasher according to claim 8:

said spring is in generally nested relation in said channel, but spacedfrom the walls forming said channel to avoid contact therebetween duringstretching and relaxing said spring.

10. In a dishwasher according to claim 8:

the end points of the arc of movement of said lever arm end portion,corresponding to said door being closed and alternatively open, liebetween planes coincident with the opposite legs forming said channel.

uALnnn

1. In a dishwasher including a forwardly-open-face tub and a door forclosing said tub face and hinged adjacent its lower edge, acounterbalancing arrangement for at least one side of said door,comprising: a lever arm fixed to said door at a side thereof adjacentthe lower portion and having an end portion movable through an arc inaccordance with door movement; a tension spring for counterbalancingsaid door at a side of said tub, said spring having a fixed lower end;means for guiding the upper end of said spring for movement along anaxis substantially coincidence with the axis of said spring; and pivotalmeans having a lower end portion connected to said upper end of saidspring, and having an upper end portion connected to said lever arm endportion so that said pivotal means pivots at both connections toaccommodate the varying perpendicular distance between said axis andpoints along said arc.
 2. In a dishwasher according to claim 1: saidguiding means includes a channel-shaped support leg for said tub, withsaid channel being outwardly open.
 3. In a dishwasher according to claim2: said arc has end points, corresponding to opposite positions of saiddoor, facing an area spanned by the width of the channel of said supportleg.
 4. In a dishwasher according to claim 2: said spring is nested inpart at least in said channel of said support leg.
 5. In a dishwasherincluding a forwardly-open face tub and a door for closing said tubface, said door having a hinge axis adjacent its lower edge, acounterbalance arrangement for at least one side of said door,comprising: a vertically-disposed leg adjacent the tub front andextending upwardly along a siDe of said tub; a lever arm fixed to theside of said door, said arm being dimensioned and located that its endportion remote from the door moves through an arc, as said door is movedbetween its opposite positions, generally following said leg; a tensionspring having its lower end fixed adjacent the lower portion of saidleg; pivotal connector means having one portion slidable along said legand having the upper end of said spring pivotally connected thereto, andhaving another portion pivotally connected to said end portion of saidlever arm and pivotal about the connection between said one portion andsaid spring so that said spring is stretched and relaxed along its axiswithout angular displacement therefrom as said end portion of said leverarm is moved throughout its said arc, said pivotal connector pivotingabout both of its said connections to accommodate the varyingperpendicular distance between said axis and points along said arc. 6.In a dishwasher according to claim 5: said leg is an outwardly-open,channel-shaped member in horizontal cross-section; and said one portionof said pivotal connector means is received at least partly in saidchannel.
 7. In a dishwasher having a forwardly-open face tub and a doorhaving a lower edge hinge axis for closing said tub, a counterbalancearrangement comprising: a lever arm fixed to each of the opposite sidesof said door, each arm having an end portion remote from said door; atension spring at each of the corresponding opposite sides of said tubfor counterbalancing said door; a vertically-disposed support leg ateach side of said tub adjacent the front thereof; means fastening thelower end of said spring to the lower portion of said leg; pivotalconnector means for connecting the upper end of said spring to said endportion of said lever arm at two pivotal connection locations, saidconnector means including a slider portion confined by said leg tomovement along an axis coincident with the axis of said spring, saidconnector means including another portion pivotally connected to saidlever arm end portion to provide one of said pivotal connectionlocations, and pivotal about the axis of connection of the upper end ofsaid spring to said connector means to provide the other of said pivotalconnection locations, both said pivotal connections pivoting during doormovement to accommodate the perpendicular distance between the axis ofsaid spring and various points along the arc of movement of said endportion as said door is moved.
 8. In a dishwasher according to claim 7:said support leg comprises an outwardly-open channel, said sliderportion being received in said channel.
 9. In a dishwasher according toclaim 8: said spring is in generally nested relation in said channel,but spaced from the walls forming said channel to avoid contacttherebetween during stretching and relaxing said spring.
 10. In adishwasher according to claim 8: the end points of the arc of movementof said lever arm end portion, corresponding to said door being closedand alternatively open, lie between planes coincident with the oppositelegs forming said channel.